Shuttle clamp for bobbins



y 2, 1957 H. w. THATCHER 3,316,942

SHUTTLE CLAMP FOR BOBBINS Filed Feb. 11, 1965 INVENTOR. HARRY \A/ILLIAMTHATCH ER A TTORNEY United States Patent 3,316,942 SHUTTLE CLAMP FOR BUBBHNS Harry William Thatcher, Mention, Mass., assignor to Draper Corporation, Hopedale, Mass., a corporation of Maine Filed Feb. 11, 1965, Ser. No. 431,827 4 Claims. (Cl. 139-207) This invention pertains to shuttles for looms and, more particularly, to the clamping means for positioning a bobbin within the cavity of a shuttle.

It is a general object of the invention to provide an improved clamping and gripping member for positioning a ringless type filling bobbin within the cavity of a loom shuttle.

A further object is that of providing a clamping and gripping member of light weight construction and which is relatievly inexpensive to manufacture.

A further object is that of providing a bobbin clamping and gripping member that is supported for its entire length within a loom shuttle.

Another object is that of providing greater stability for a bobbin within a shuttle by providing extended gripping and clamping of the bobbins butt portion.

A still further object is that of providing a bobbin clamping and gripping member which, as compared to shuttle springs of the prior art, provides a relatively higher resistance to the longitudinal forces which a bobbin is subjected to during the picking and boxing of a loom shuttle.

Further objects and advantages of the invention will become apparent from the following more detailed disclosure.

Shuttles of the type utilized in looms of the automatic bobbin changing models are provided with a so-called shuttle spring which in a known manner is fixedly positioned in a recess provided at one end of a shuttle. The more common form of shuttle springs employed are those having opposed jaw members with aligned grooves adapted to receive and hold a filling bobbin by the plurality of rings assembled on the butt portion of said bobbin. This type of spring has a U-shaped shank portion that is adapted to fit into a pocket machined from the shuttle material and is held therein by means of a horizontally disposed bolt and so-called spring cover.

Shuttles for present-day looms are made as large as is considered practical, for it is considered feasible to utilize as large a filling supply in a shuttle as it is capable of carrying. The increased speeds and work loads that looms are now subjected to have left a great deal to be desired with regards to an improved means of clamping and maintaining a filling bobbin within an operating shuttle.

The conventional type of shuttle springs as heretofore described are now subjected to greater demands and the life expectancy therefore is considered inappropriate relative to the operating life of the shuttle itself.

Shuttle spring failure may take a variety of forms, e.g., the spring may fail due to breakage and the opposed clamping grooves can become worn to the extent of losing its effective gripping properties, whereby longitudinal movement of the filling bobbin within the shuttle will develop. This longitudinal movement of a bobbin is referred to by those conversant in art as groove jumping and can be attributed to the sudden accelerating of picking and the abrupt stopping by shuttle boxing. The manice ner in which this type of spring is assembled within a shuttle allows a substantial portion of the length thereof to extend unsupported into the bobbin cavity of the shuttle. This so-called overhang of the shuttle spring and the repeated hammer blows of the transferrer are instrumental in causing a spring to become loosened in the shuttle. A spring which has become tilted does not allow the bobbin being gripped thereby to be held in a true horizontal plane and often results in filling breakage when the filling cannot be withdrawn freely from said bobbin. Springs which have become faulty as described above can create more serious problems if not detected soon enough for adjustment or replacement. A filling bobbin being gripped by a worn shuttle spring or one which has become loosened can, by the accelerating forces of picking as well as the abrupt stopping of the shuttle by boxing, cause said bobbin to tilt to the extent of causing interference with the warp threads as it travels through the shed formed thereby. An interference of this nature will tear out many warp threads creating what is known as a smash resulting in an excessive amount of loom downtime necessary to place the loom in operating condition.

The bobbin support and gripping member according to the instant invention has to a great extent alleviated the above-mentioned problems which are rather common sources of annoyances.

This support and gripping member is preferably made from an elastomeric material such as polyurethane and is formed so as to grip and position firmly the butt portion of a ringless type bobbin within a loom shuttle. The shuttle itself is provided at one end of the bobbin opening with opposed and vertically spaced shelf members within the confines of which the support and gripping member is adapted to assembled. The shelf members support the gripping member for its entire length and the outer sides of said member contact the side walls of the shuttle to provide additional support.

This gripping member is generally U-shaped with the internal surfaces thereof conforming generally to the shape of a bobbin butt. The free ends of the gripping member are directed inwardly and extend into close proximity with the barrel portion of the bobbin and firmly position the bobbin against any possible longitudinal movement.

The holding and gripping properties of the clamping member are functions of the urethane tension modulus of said member and results of development trials indicate greatly improved bobbin gripping and positioning properties relative to the conventional shuttle spring heretofore described.

The invention will hereinafter be described in greater detail by reference to the accompanying figures of drawing in which:

FIG. 1 is a plan view of a portion of a loom shuttle showing the clamping and gripping member according to the invention applied thereto;

FIG. 2 is a detail plan view of the clamping and gripping member shown in FIG. 1;

FIG. 3 is a view in side elevational of the member shown in FIG. 2; and

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.

Now referring to the figures of drawing, there is shown in FIG. 1 a portion of a loom shuttle 10 having the usual 3 illing bobbin cavity 11 which extends longitudinally for 1 portion of the length of said shuttle.

A bobbin support and gripping member generally in- :licated by numeral 12 is fixedly positioned in and at one and of the cavity 11 and as shown in FIG. 1 is adapted to receive and maintain a filling bobbin 13 in proper operating position within a shuttle.

As shown in FIGS. 1 and 2 this support and gripping member is generally U-shaped, defining opposed gripping elements 14 and 15 which are interconnected at one end thereof by an integrally formed arcuated end portion 16 (FIGS. 1 and 2). The opposite ends of these gripping elements terminate with integrally formed retaining projections 17 and 18 which extend inwardly leaving only sufficient clearance therebetween to permit the barrel portion of the bobbin 13 to extend therethrough from its butt portion which is adapted to be retained within and by the combination of elements identified by numerals 14, 15, 16, 17, and 18 (FIG. 2). The opposed gripping elements 14 and 15 are provided on their inner sides with centrally disposed and longitudinally extending concave surfaces 19 and 29 (FIG. 4) which are of a lesser diameter than the diameter of the butt of the bobbin 13.

The distance between these gripping elements is slightly less than the diameter of the bobbin butt and when the latter is forced therebetween at time of transfer, the elastomeric material from which the bobbin support and gripping member is made, is caused to be displaced causing the compression modulus of said material to grip and firmly hold said butt against lateral or rotary movement.

The distance between the inner surface of the retaining projections 17 and 18 and the inner surface of the end portion 16 is slightly less than the length of the bobbin butt and the tension modulus of this material acts upon the end portions of the bobbins butt to firmly grip the same and prevent longitudinal movement thereof.

To facilitate the displacement of this elastomeric material, which in the instant case is preferably a polyurethane, the outer sides of the opposed gripping elements 14 and 15 which contact the walls of the shuttle are provided with vertically spaced and longitudinally extending displacement recesses 21 and 22, respectively. To further facilitate the displacement of this material vertically disposed recesses 23 and 24 are provided on the inner and end portions of the opposed gripping elements 14 and 15 (FIG. 2).

To assure positive entry and ejection of a bobbin butt into and from the support and gripping member 12 without interference, the entire upper and lower extent of the opening adapted to receive and expel said butt are tapered as at 25 and 26 (FIG. 4). I

The means by which this bobbin support and gripping member 12 is fixedly positioned within the cavity of a :shuttle includes vertically spaced shelf members 27 and 128 (FIG. 1 and 4) which form a part of the side walls of the shuttle 10. These shelf members define opposed recesses R and the width thereof is sufficient to permit a :sliding fit of the gripping member therebetween and said :shelf members are interconnected by the end of the cavity. The distance between the shelf members extends beyond the end of the cavity defining a pocket 29 (FIG. 1) which conforms to the configuration of the end portion 16 of the gripping member. This pocket is adapted to receive the end portion 16 of gripping member and the latter is secured therein by means of one or more vertically disposed cap screws 30 (one only shown in FIG. 1). These cap screws enter the shuttle through an appropriate aperture (not shown) disposed at the lower side thereof and being centrally located relative to the pocket 29, the threaded portions thereof are adapted to be received into aligned threaded holes 31 provided in the end portion 16 of the gripping member. T provide a positive anchoring of the threaded portion of set screws .31), metallic threaded inserts (not shown) are molded into the end portion 16 during manufacture of the gripping member itself.

In operation, the shuttle is picked to and fro through the shed formed by warp threads in the conventional and well-known manner. When an indication is given for filling replenishment, a new bobbin is transferred into the bobbin cavity of the shuttle and the spent bobbin is ejected in the usual manner. The inwardly tapered upper portion of the gripping member is instrumental in guiding and properly positioning a new bobbin in the desired operating position within the shuttle. The outwardly tapered lower portion of the gripping member permits the spent bobbin to be ejected free of interference. Those surfaces of the gripping member disposed intermediate the upper and lower tapered portions are effective through the tension modulus of the elastomeric material from which said member is made to firmly grip and hold a ringless type bobbin in a true horizontal plane during loom operation. The gripping surfaces are so disposed about the butt of the bobbins so as to prevent any lateral, rotary, or longitudinal movement of the bobbin which are rather common sources of annoyance with the prior art type of shuttle spring heretofore described.

The novel means of securing the gripping member within a shuttle has eliminated that undesirable condition of shuttle spring loosening and tilting.

The fact that the gripping member is supported for its entire length by the integrally formed shelf members prevents any possibility of said member from becoming tilted and also permits it to be fixedly positioned by means of one or more vertically disposed screws rather than the conventional combination of vertical and horizontally disposed bolts. These horizontally disposed spring retaining elements have been another source of annoyance for in the event of springs loosening said elements will work outwardly to the extent of interfering with proper shuttle boxing.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. For a loom shuttle having a longitudinally extending, bobbin receiving and ejecting opening, opposed and vertically spaced and horizontally extending shelf members forming one end of said opening and extending for a portion of the length thereof, said shelf members defining a recess in each of the side walls of said shuttle within said opening, a bobbin support and gripping member receivable by and adapted to be fixedly positioned in abutting relationship with said recesses formed by said shelf members, said bobbin support and gripping mem her having a cross sectional configuration conforming to said openings one end, and being generally U-shaped to define opposed gripping elements adapted to extend within the longitudinal extent of said recesses, the inner surfaces of said member including centrally disposed and longitudinally extending concave surfaces forming vertically spaced and opposed gripping points for the butt of a loom bobbin.

2. The shuttle according to claim 1 wherein said recesses are interconnected by a pocket formed in said shuttle and cooperating with said opening.

3. The shuttle according to claim 2 wherein said pocket conforms to the configuration of the end of said gripping member and having means cooperating therewith for fixedly positioning said member therein.

4. The shuttle according to claim 1 wherein those surfaces of said bobbin "support and gripping member in abutting relation with the sides of said opening within the recesses formed by said shelf members include horizontally disposed and longitudinally extending displacement recesses for the expansion and contraction of said member during the receiving and expulsion of a bobbin therefrom.

References Cited by the Examiner UNITED STATES PATENTS 855,514 6/1907 Jackson 139-207 1,333,397 3/1920 Egli 139-207 3,048,197 8/ 1962 Fink 139207 6 2/1966 Klocker et a1. 139-407 FOREIGN PATENTS 1/ 1923 France.

1/1924 Great Britain.

3/1964 Great Britain. 12/ 1933 Italy. 

1. FOR A LOOM SHUTTLE HAVING A LONGITUDINALLY EXTENDING, BOBBIN RECEIVING AND EJECTING OPENING, OPPOSED AND VERTICALLY SPACED AND HORIZONTALLY EXTENDING SHELF MEMBERS FORMING ONE END OF SAID OPENING AND EXTENDING FOR A PORTION OF THE LENGTH THEREOF, SAID SHELF MEMBERS DEFINING A RECESS IN EACH OF THE SIDE WALLS OF SAID SHUTTLE WITHIN SAID OPENING, A BOBBIN SUPPORT AND GRIPPING MEMBER RECEIVABLE BY AND ADAPTED TO BE FIXEDLY POSITIONED IN ABUTTING RELATIONSHIP WITH SAID RECESSES FORMED BY SAID SHELF MEMBERS, SAID BOBBIN SUPPORT AND GRIPPING MEMBER HAVING A CROSS SECTIONAL CONFIGURATION CONFORMING TO SAID OPENING''S ONE END, AND BEING GENERALLY U-SHAPED TO DEFINE OPPOSED GRIPPING ELEMENTS ADAPTED TO EXTEND WITHIN THE LONGITUDINAL EXTENT OF SAID RECESSES, THE INNER SURFACES OF SAID MEMBER INCLUDING CENTRALLY DISPOSED AND LONGITUDINALLY EXTENDING CONCAVE SURFACES FORMING VERTICALLY SPACED AND OPPOSED GRIPPING POINTS FOR THE BUTT OF A LOOM BOBBIN. 